Contra-angle retainer for use with gingival-aperture and cusp-replacing dental matrix bands



A ril 8, 1952 B. F. TOFFLEMIRE 2,591,745 CONTRA-ANGLE RETAINER FOR USE WITH GINGIVAL-APERTURE AND CUSP-REPLACING DENTAL MATRIX BANDS Original Filed Dec. 12', 15 350 INVEN TOR.

ATTORNEYS Patented Apr. 8, 1 952 CONTRA-ANGLE RETAINER FOR USE WITH GINGIVAL-APERTUIQE AND CUSP-REPLAC- ING DENTAL MATRIX BANDS Benjamin F. Tofflemire, Lafayette, Calif.

Original application December 12, 1950, Serial No. 200,411. Divided and this application January 9, 1951, Serial No. 205,143 l V 3Claims. (01. 32 -53) The present invention relates to improvements in a retainer adapted for use with a gingivalaperture and cusp-replacing dental matrix band. It relates to divisible subject matter disclosed in my copending application, entitled Gingival- Aperture Dental Matrix Band, which was filed in the United States Patent Office on December 12, 1950, Serial No. 200,411.

Moreover, the retainer shown herein embodies structural improvements over the retainers illustrated in my United States Letters Patent No. 2,439,703, dated April 13, 1948, and No. 2,502,903, dated April 4, 1950.

In the copending application identified above, I provide a dental matrix band,'which is adapted to be looped around an axial contour of a tooth to be restored. This band is fashioned with an aperture through which filling material may be inserted into a gingival cavity of the banded tooth. It is essential that such a band be maintained in snug embracing relation with the axial contour of the tooth during the restoration.

The retainer to be covered in the instant application is provided with a slotted head, which defines a plurality of guide fingers. With the band looped around a tooth, the intermediate portions of the band are guided by these fingers to a clamping block. The latter is movable along a bar-like frame away from or toward the slotted head for constricting or expanding the loop, respectively.

An object of this invention is to provide a retainer, with a definite off-set angle that may be usedfor holding a matrix band around a posterior (back) tooth, with the bar-like frame clearing the anterior (front) teeth. This situation prevails when the loop ofthe band is disposed laterally to one side of the retainer.

Further, when the retainer is directed generally across the mouth, aiid the band is applied arounda posterior tooth in one quadrant, the retainer'will clear the patients tongue and the occlusal surfaces of the posterior teeth in an opposite quadrant.

in either event, the portion of the slotted head thatv fits up against the lingual (tongue-side) ofthe tooth is shaped to follow the contour of thebanded tooth.

Briefly stated, the guide fingers are inclined with respect to the lengthbf the bar-like frame. This angular arrangement will permit the fingers to remain parallel with the long axis of the tooth, while the retainer itself is permitted to extend at an inclination to clear the incisal edges of the anterior teeth, or p-atients tongue and the occlusal surfaces of the posterior teeth at the opposite side of the patients mouth.

'l2--lingual surface (tongue-side) Other objects and advantages will appear as the specification continues. The novel features of the invention'will be set forth in the claims hereunto appended.

Drawing For a better understanding of my invention, reference should be had to the accompanying drawing, forming part of this application, in which:

Figure 1 is an isometric view of my improved retainer adapted for securing the dental matrix band around a tooth;

Figure 2 is a face view of one of my flattenedout bands;

Figure 3 is an occlusal view of the lower quadrants, illustrating the band applied around the right second bicuspid, and held in place by my retainer; I

Figure 4 is an elevational view of the retainer, taken along the plane IV-IV of Figure 3, parts being shown in section;

Figure 5 is a fragmentary plan view of the forward part-of the retainer; and

Figure 6' is a bucco-lingual sectional view taken along the plane VI-VI of Figure 3.

WhileI have shown only the preferred form of my'invention, it should be understood that various-changes, or modifications, may be made within the scope of the annexed claims without departing from the spirit thereof.

Detailed description Referringto Figure 3 of the drawing, itwill be noted that the teeth in the lower quadrants are illustrated therein. The anterior (front) teeth Ainclude central incisors, lateral incisors and cuspids, respectively, starting at the mesial plane ID of the body and advancing toward the outer ends of the quadrants. The posterior (back) teeth B include the first bicuspids, second bicuspids, first molars, second molars, and third molars or wisdom teeth.

The tooth B in Figure 3, which has been encircled by my improved dental matrix band C (full-line illustration), is a lower right second bicuspid. This band is held in place by my retainer D, which forms the subject matter of the present application.

The following anatomical parts of the second bicuspid. B are identified as follows (see Figures 3 and 6) ll-buccal surface (toward the cheek) l3mesial surface (toward the mesial plane) I l-distal surface (remote or away from the mesial plane) l5occlusal (grinding) surface; and l6--gin- The mesial and distal surfaces l3 and I4, respectively, have a decided pitch, flaring outwardly from the neck I! of the bicuspid to the occlusal surface [5. In Figure 6, the buccal and lingual surfaces H and I 2, respectively, have a moderate or slight upward flare. Human teeth are not round in cross section, but are characterized by a decided mesio-distalflattening or constriction at the interproximal; (between the teeth) gingival curvature or border I6. Both molars and. bicuspids have this mesio-distal constriction in common.

In order that the use of. my. retainer. may be, fully understood, the details of my matrix. band.

C will be set forth briefly. Figure 2 illustrates a flattened-out view of this flexible band. In its structural features, an arcuate central portion l8 has arms I9 projecting outwardly therefrom in diverging relation with one another. The occlusal-facing and gingival-facing edges, respectively, of the band are designated at and 2|. It will be noted that the central portion I8 is concaved and convexed on its occlusalfacing and gingival-facing edges, respectively, while the arms i9 are straight. The gingivalfacing edges 2| are undercut, as at 22, so as to follow the gingival borders 16 of a banded tooth in the interproximal areas. An elongated aperture..23.pierces thearcuate central portion IS. The band is substantially uniform in width throughout its entire length.

As shown in Figure 6, a bucco-gingival cavity E has been prepared in the bicuspid B and my dental matrix band C applied thereover. The aperture 23 of the band registers with this cavity, but is somewhat smaller so thatanencapsulating section 24 of the band will be disposed occlusally above the cavity. A gingival section of the band provides a sub-gingiva-l extension 25 that projects below the free gingival tissues 26 ,when the band is looped around the tooth.

The prepared buccal cavity E shows axial retention locks 21 at the base of this cavity so as to retain a filling F therein. The material for the filling may be of any suitable type, for instance amalgam. An intermediate, cement base 28 may be, inserted into thecavity before the filling material is introduced.

Referring to the details of the retainer D, it includes a bar-like frame 29 on which a matrixclamping block 39 is slida-bly mounted. This frame has a head}! at its forward end. which defines four parallel and spaced-apart fingers 32. The arms 19 of the matrix band are adapted to be introduced edgewise into a diagonally.- extending slot -33 formed in the block 30, and clamped thereto by the pointed end 34 of, a spindle 35 that is threaded into the block (see Figures 4 and5). This spindle is rotated by an operating-knob 35.

A rotatable internally-threaded sleeve 3? is held against endwise movement relativeto the frame 29. Thisis accomplished by apair of fingers 38 that project into an annular groove 39 formed in the sleeve 37 (see Figure 4) When the sleeve is turned, the spindle 35 and clamping block are advanced or retracted relative-to the head 3|.

' In-the full-line illustrations of the retainer D in Figured, the arms I9 of the band extend through a lateral slot 40 defined between a lateral pair of the fingers 32 (see Figure 5). It will be observed that the lateral pair of the fingers are concaved, both. horizontally and-vertically, as

at 4| (see Figures 5 and 6), fonfitting .up. against.

the lingual or buccal surfaces of the banded tooth, and to follow the tooth contour when the band is drawn into place. This full-line showing of the retainer in Figure 3 may be referred to as a lateral hook-up.

It is quite apparent that when the band and retainer are used in conjunction with posterior teeth B of the left quadrant in Figure 3, the band. ends l9 may be guided through a lateral slot 42 (see Figure 5) provided between another set of the. lateralfingers 32 (see top of Figure 5).

Referring to Figures 5 and 6, it will be seen that these fingers have concaved edges 43, which are curved horizontally and vertically and shaped to. conform with the lingual or buccal surfaces of the. tooth a i t which they are to be drawn. The edges 43 are disposed flush with the outer lateral surface 29a of the bar-like frame 29 (see Figure 5). This will permit the surface 43 to be moved. up againstthe banded tooth without interference by the frame.

The dot-dash line illustration in Figure 3-shows an end hook-up, with the retainer being directed across the mouth. In this case,.the arms 19 of the matrix band are guided through a front slot 44 defined between the forward pair. of fingers 32 (see Figures 1 and 5). The latter'have concaved faces 45 shaped to conformto the surface of the tooth upon. which the matrix band is applied. With either a lateral or an end hook up, the arms [9 of the matrix band extend through a rear slot 46 (see Figure 5), the latter being provided between the rearmost guide fingers.

It will'be noted from Figuresl and 4 that the length of the guide fingers 32 are inclinedwith respect to the length of the bar-like frame 29. This angular arrangement will perm-it the fingers of the retainer to remain parallel with the long axle of the tooth, while the retainer itself is permitted to extend upwardly to clear the incisal edges of the anterior teeth A, as shown in Figure 4. When using an end hook-up, as in the dot-dash line illustration in Figure 3, the inclined arrangement of the fingers 32 will allow concaved edges of the latterto adapt themselves to the lingual contour of the toothfwhile the retainer. clears thetongue and the occlusal surfaces of the teeth B onthe" opposite sideof the mouth.

In either case, it will be noticed that I have made provision for the portion of the head 3| fitting up-against the-lingual or buccal surfaces of the banded tooth, following the contour of the latter.

While most'of these .difficult gum-line cavities occur on the bucco-gingival aspect ll, theydo occur. on the lingual surface [2. Theaperture side of the band C, insuch a case, simply. is placed on the lingual side of the tooth and-the retainer D applied from the buccal, or a reverseposition to the one shown in thedrawing.

It will be noted that the head3| has itsslots 4G, 42, 44 and 46 extending thereinto from an exposedsurface of the head whereby intermediate sections of the matrix band-C may be telescoped edgewise into selected slots. Moreover, this headprojects laterally 0f the bar-like frame 29 and is confined to one side thereof.

The block 30 extends laterally of the frame on the same sideof the latter as the head. The diagonal slot 33 extends into the block'from an exposed surface of the block, and closely confines the. end portionsof the band arms .19.. The slot 33 is arranged onthe .same-sidebfthefr'ame .29

as the head 3 Land extends from a forward end 30a to an unobstructed face 30b at the side of the block opposite to the frame 29 (see Figure The slots in the head and clamping block open toward a common plane and are dimensioned for edgewise insertion of the matrix band thereinto. Thus, it .is apparent that the bar like frame 29 is disposed to give free access from above, below and laterally to the portions of the matrix band disposed between the head and the block for unobstructed manual grasping and vertical shifting of these band portions by an operator during insertion or removal of the band. The guide fingers 32 extend downwardly and forwardly, when the retainer is applied to .bands encircling the lower teeth. Of course, the instrument is inverted from that shown in Figure 4 when banding upper teeth.

Summary of operation Assuming that the bucco-gingival cavity E on the lower right second bicuspid B is to be filled,

the cavity is prepared by the dentist in the usual way, including the axial retention locks 21.

After the cavity has been completed, the matrix band C is looped, with the arms l9 thereof arranged parallel and in abutting relation with respect to one another. Thereupon, the end portions of these arms are inserted edgewise into the diagonal slot 33 of the block 30. The intermediate portions of the arms are inserted through the rear slot 46 and the lateral slot 40, theseslots being .defined by the guide fingers 32.

Next, the operating knob 36 is turned so as to advance the spindle 35 until th pointed end 34 of the latter clamps the arms 19 of the band to the block 30. Now the dentist telescopes the looped part of the band downwardly over the tooth B until the sub-gingival extension 25 is "inserted into the tooth socket below the free gingival (gum) tissues 26, as shown in Figure 6 of the drawing.

At this time, the sleeve 31 is rotated 50 as to retract the block 30 away from the head 3|, until the band snugly embraces the entire axial contour of the-banded tooth. This will result in bringing the concaved edges 4| of the fingers up against the band. The bar-like frame 29 of the retainer will extend upwardly at an angle so as to clear the incisal edges of the anterior teeth A, as shown in Figure 4.

When using the retainer for an end hook-up" as suggested by the dot-dash line position of the instrument in Figure 3, the loop of the matrix band extends forwardly from the head 3|, the arms I9 of the band extending rearwardly through the slots 44 and 46 to the clamping block.

In this dot-dash illustration, a second molar B" in the right quadrant has been banded. The instrument will clear the patients tongue and the posterior teeth in the opposite quadrant, due to the inclination of the fingers 32 relativ to the bar-like frame.

. Banding of a posterior tooth in the left quadrant of Figure 3, from the lingual aspect, may be accomplished by having the loop of the band extend laterally from the curved edges 43 of the retainer head.

An additional, and very important use, of this new contra-angle retainer, is found in restoring entire cusps and missing compound-angles of bicuspids and molars, using arcuate bands in the retainer, which is applied from the lingual aspect of the teeth.

I claim:

1. In a dental matrix retainer: a bar having-a slotted head at a forward end thereof; this head defining a plurality of guide fingers, with slots provided between adjacent fingers; these slots being arranged for slidably-receiving intermediate overlapped portions of a looped dental matrix band, with the loop projecting beyond the head to encircle the axial contour of a posterior tooth; the length of the bar being inclined relative to the lengths of the fingers so that the bar will clear incisal edges of anterior teeth, or clear the patients tongue and occlusal surfaces of posterior teeth in an opposite quadrant whenthe bar is directed across the patients mouth, with the finger lengths paralleling the long axis ofthe banded tooth in either case; and means engageable with end portions of the band for drawing the intermediate band portions between the guide fingers to constrict the loop about the banded tooth. V i

2. In a dental matrix retainer: a bar having a slotted head at a forward end thereof; this head defining a plurality of guide fingers, with slots provided between adjacent fingers; these slots being arranged for slidably-receiving intermediate overlapped portions of a looped dental matrix band, with the loop projecting beyond the head to encircle the axial contour of a posterior tooth; the length of the bar being inclined relative to the length of the fingers so that the bar will clear incisal edges of anterior teeth, or clear the patients tongue and occlusal surfaces of posterior teeth in an opposite quadrant when the, bar is directed across the patients mouth, with the finger lengths paralleling the long axis of the banded tooth in either case; and means engageable with end portions of the band for drawing the intermediate band portions between the guide fingers to constrict the loop about the banded tooth; the fingers being concaved both horizontally and vertically to follow the contour of the banded tooth when they are drawn up thereagainst.

3. In a dental matrix retainer: a bar having a slotted head at the forward end thereof; this head defining a pair of fingers having lateral edges disposed flush with an outer lateral surface of the bar; the head providing a slot between the fingers arranged to slidably-receive intermediate overlapped portions of a looped dental matrix band, with the loop projecting beyond the head to encircle the axial contour of a posterior tooth; these lateral edges of the fingers being concaved both horizontally and Vertically to follow the axial contour of the banded tooth when they are drawn up thereagainst; the length of the bar being inclined relative to the lengths of the fingers so that the bar will clear incisal edges of anterior teeth, or clear the patients tongue and occlusal surfaces of posterior teeth in an opposite quadrant when the bar is directed across the patients mouth, with the finger lengths paralleling the long axis of the banded tooth in either case.

. BENJAMIN F. TOFFLEMIRE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,232,236 Hlavac et a1 Feb. 18, 1941 2,502,903 Toffiemire Apr. 1950 

